A CMOS battery is a small, coin-shaped battery that powers the CMOS (complementary metal-oxide-semiconductor) chip on a computer’s motherboard. The CMOS chip stores the computer’s BIOS (basic input/output system) settings, such as the time and date, hard drive configuration, and other system parameters. When the CMOS battery dies, the BIOS settings are lost, which can cause the computer to have problems starting up or running properly.
It is important to replace the CMOS battery every few years to prevent the BIOS settings from being lost. Replacing the CMOS battery is a relatively simple process that can be done in a few minutes.
